Abstract
Forty-five cases of bovine abortion were examined using in situ hybridization (ISH) with a biotinylated DNA probe specific for bovine herpesvirus-1 (BHV-1). Of the 45 cases, 16 were diagnosed as due to BHV-1, 15 were determined to be due to other causes, and 14 were of undetermined etiology. Direct comparisons between ISH and an immunoperoxidase (IP) test specific for BHV-1 were performed on formalin-fixed, paraffin-embedded tissue sections of lung, liver, kidney, spleen, thymus, and placenta; fluorescent antibody tests for BHV-1 and virus isolation were performed on fresh lung and liver. In comparison to these routine BHV-1 detection techniques, ISH had an overall sensitivity of 88.2% and a specificity of 89.3% in detecting BHV-1 in aborted fetuses. Immunoperoxidase was more sensitive than ISH with tissue sections from lung (87.5% vs. 69%), liver (92% vs. 17%), spleen, and placenta; results of the tests on tissue sections from kidney were concordant. Liver sections presented special problems in that nonspecific reactions were frequently observed with hybridization. With thymus sections, the rate of detection was higher by hybridization than by IP, but the specificity of some of these reactions could not be confirmed.